Technical Field
The present disclosure relates generally to catalytic converters, more particularly, to zero platinum group metals Diesel Oxidation Catalysts.
Background Information
Emission standards for unburned contaminants, such as hydrocarbons, carbon monoxide and nitrogen oxide, continue to become more stringent. In order to meet such standards, Diesel Oxidation Catalysts (DOCs), lean NOx traps (LNTs) and Continuously Regenerating Traps (CRTs) are used in the exhaust gas lines of internal combustion engines. These catalysts promote the oxidation of unburned hydrocarbons and carbon monoxide as well as the oxidation of nitrogen oxides in the exhaust gas stream to reduce engine generated pollutants. Oxidation of NO to NO2 may be used for the removal of carbon soot in CRTs. One of the major limitations of current catalysts is that the Platinum Group Metals (PGM) used in their fabrication have very high demand and increasing prices.
Therefore, there is a continuing need to provide cost effective catalyst systems that provide sufficient conversion so that HC, NOx, and CO emission standards can be satisfied, minimizing the amount of PGM catalysts required.